package com.mrwang.example.nettyinaction;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandler.Sharable;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.util.CharsetUtil;

@Sharable
public class EchoServerHandler extends ChannelInboundHandlerAdapter{

//⇽---标示一个Channel-Handler可以被多个Channel安全地共享 public class EchoServerHandler extends ChannelInboundHandlerAdapter {

	@Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) {
        ByteBuf in = (ByteBuf) msg;
        System.out.println(
            "Server received: " + in.toString(CharsetUtil.UTF_8));   //  ⇽---  将消息记录到控制台       

        ctx.write(in); //⇽---将接收到的消息写给发送者，而不冲刷出站消息

    }

	@Override
    public void channelReadComplete(ChannelHandlerContext ctx) {
        ctx.writeAndFlush(Unpooled.EMPTY_BUFFER)
            .addListener(ChannelFutureListener.CLOSE); //⇽---将未决消息冲刷到远程节点，并且关闭该Channel
    }

	@Override
    public void exceptionCaught(ChannelHandlerContext ctx,
        Throwable cause) {
        cause.printStackTrace();  //   ⇽---  打印异常栈跟踪
        ctx.close();//⇽---关闭该Channel
    }
}
